import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int g = x % 10;
		int s = x / 10 % 10;
		int b = x / 100;
		int sum = g + b;
		System.out.println(sum);
	}
}
/**************************************************************
	Problem: 1614
	User: admin
	Language: Java
	Result: Accepted
	Time:773 ms
	Memory:40204 kb
****************************************************************/